1. Field of the Invention
The present invention relates generally to apparatus for filling containers and more particularly to improved means for filling capsules as well as an improved method for filling capsules.
2. Description of the Prior Art
One very important example of the prior art in the field to which the present invention is directed is my own issued U.S. Pat. No. 3,675,390 granted on July 11, 1972. In my prior patent I disclosed a capsule filling machine that includes a rotatable turret having capsule engaging openings that are movable with the rotation of the turret successively through a capsule feeling station, a capsule opening station, a capsule filling station, a capsule closing station and a capsule discharge station. Capsule opening members also have capsule engaging openings and are also movable with the turret and are movable relative to the turret between closed advance positions proximate the turret with the capsule engaging openings in the turret and the capsule opening members in axial alignment and open retracted positions that are remote from the turret. Acutating means urge the capsule opening members to their closed positions at the capsule feed and the capsule closing stations and to their open positions at the capsule feeding stations. In my prior patent means are provided for feeding individual closed capsules at the feeding stations with the lower and upper sections thereof separating into respective engagement with the openings in the turret and the capsule opening members so that the vacuum opens the capsule lower sections.
In my prior issued U.S. Patent the turret is in the form of a rotatable drum that is supported at its rear end which is provided with circumferentially spaced radial bores. The capsule opening members in the preferred embodiment of my prior U.S. patent comprise longitudinal arms that are pivoted to the rear end of the drum and which are swingable between advanced positions that are superimposed on the drum face and retracted outwardly directed positions. The arms also have bores that are in axial alignment with the bores on the turret when the arms are in the advanced position. A cam which is located rearwardly of the drum and which is engaged by cam followers mounted on the arm retract the arms between the capsule opening and the capsule closing stations. A capsule feed pipe has a discharge opening that registers with each bore in the arms at the capsule feed station and suction means communicate through the drum underface with the first bores in the turret at the capsule feed station. A filler feed tube engages the drum outerface and communicates with each first bore in the drum at the filler station and an outwardly spring biased pusher member inside the drum at the capsule closing station bears on the inner end of a capsule in order to close the capsule. A shoe slidingly engaging the arm outerfaces bordering the bores in the arm opposite the pusher member prevents the capsule cap from moving outwardly. A spring loaded ejector finger moves in and out of the discharge station with the drum rotation.
While the construction illustrated in my prior U.S. patent was acceptable, it has been found that improvements may be made thereto that will provide greater reliability, ease of handling and speed of production. It is to these improvements that the present invention is directed.
Another example of the prior art to which the present invention is directed is described in U.S. Pat. No. 3,070,932 granted on Jan. 1, 1963 to Otto Hofliger. In U.S. Pat. No. 3,070,932 there is disclosed an apparatus for filling and sealing capsules each of which consists of a cup shaped base and a cup shaped cap. In the Hoflinger apparatus a pair of disks are mounted for intermittent rotary motion about spaced parallel axes which are spaced from each other such that a portion of one disk overlaps a portion of the other disk. The overlapping disk is formed with a plurality of grooves arranged in a plurality of groups for receiving the capsules. The overlapped disk is formed with a plurality of recesses arranged in a plurality of groups for receiving the base members of the capsules. The overlapping portions of both disks define first and second transfer stations at which each groove in one group of grooves is vertically aligned with each recess of one group of recesses during the intervals between the intermittent movement of the disks. Means are provided for dispensing empty capsules into the grooves of the overlapping disk whereby each groove at the first transfer station contains empty capsules. Means are located at the first transfer station for moving the capsule base members into the recesses of the overlapped disk. The capsules are filled intermediate adjacent transfer stations and means at the second transfer station are provided for returning the filled capsule base members from the recesses into the grooves positioned thereabove. It will be appreciated from the foregoing that only intermittent motion of the disks is provided in the Hofliger patent whereas, as will be made evident from the description of the present invention which will follow, means are provided herein for continuous rotary motion.
U.S. Pat. No. 1,993,716 granted on Mar. 5, 1935 to W. A. Hanley et al. discloses another form of capsule filling machine. In the Hanley et al patent there is provided two overlapping disks that are rotatable about parallel axes. One of the disks is provided with a circumferential series of holes that are adapted to receive the capsule caps while the other of the disks is provided with a circumferential series of holes that are adapted to receive the capsule bodies. The disks are rotated intermittently. The disks, the holes and the rotating means are arranged so that when the disks are at rest, two cap-receiving holes will be aligned with two body-receiving holes. Feeding means are included for positioning an assembled capsule in one pair of aligned holes when the disks are at rest. Means are also provided for separating the capsule body from the capsule cap in order to leave the capsule cap in the first disk and the capsule body in the second disk. The capsule bodies are filled as they are carried between the positions in which they are separated from their respective caps to the other position in which the holes in both disks are aligned. The caps and the bodies are subsequently joined to each other and the capsules are then ejected. It will be evident from the foregoing that the Hanley et al. patent, like the Hofliger patent teaches the use of intermittent, rotary motion, which is but one of the distinctions of the present invention over the prior art.
Another form of the prior art in the field to which the present invention is directed is disclosed in U.S. Pat. No. 2,630,953 granted on Mar. 10, 1953 to A. W. Kath. In the Kath patent there is provided a capsule filling machine that is free of intermittent movement and which is operable continuously to perform upon multiple groups of capsules all of the required operations of separation, filling, rejoining and ejection. The Kath patent provides a rotatable disk carrier having a series of apertures disposed perpendicular to the plane of the disk for receiving capsule bodies. A plurality of center plate carriers are movably mounted in superimposed spaced relationship circumferentially about the disk carrier with each of the centerplate carriers having a series of apertures coaxially aligned with a corresponding counterpart segment of the body receiving apertures for receiving capsule caps. Means are providing for driving the carriers in rotation about a common axis. Means are also provided for maintaining the cap and the body receiving apertures constantly in coaxial alignment. In addition, means for displacing the carriers one from the other in a direction perpendicular to the plane of the disk carrier during rotational movement is also provided. Means are further provided for reciprocally moving the sector plate cap carriers away from and towards the body carrying disk carrier in a direction perpendicular to the plane of the disk carrier and in timed relationship. It will be evident from the foregoing that while Kath eliminates the intermittent motion described in the Hanley et al and the Hofliger patents other structural drawbacks are introduced. For example, in the Kath patent the carriers must be displaced from one another in a direction perpendicular to the plane of the disk carrier. This requires a complex and costly mechanism that is subject to failure when operated for long periods of time and at high speed. Furthermore, means must be provided for maintaining the cap and body receiving apertures constantly in coaxial alignment. This too is difficult to achieve in high speed machinery so that, should there be any misalignment, stoppages of the machine must occur with attendant loss in production time.
Yet another example of prior art in the field to which the present invention is directed is disclosed by R. W. Smith in U.S. Pat. No. 2,412,637 granted on Dec. 17, 1946. In the Smith patent a cylindrical capsule body carrier is provided with longitudinal rows of radial holes about its periphery. The holes are adapted to receive capsule bodies. A plurality of arcuate plates are slidably mounted for axial movement on the periphery of the cylindrical capsule body carrier with the arcuate plates having longitudinal rows of radial holes adapted to be aligned with the holes in the capsule body carrier and to receive capsule caps. Means are provided to rotate the carrier and the plates and to axially slide each of the plates in one direction in order to misalign the capsule caps and bodies so that a row of capsule bodies is exposed as the individual plate rotates to a predetermined position. Means are further provided to axially slide each of the plates in a second direction and realign the capsule caps and bodies as the individual plates rotates through a second predetermined position whereby at any one instant as the carrier and the plates are rotated, some of the plates are misaligned and some of the plates are aligned. Means are also provided to separate the capsule bodies and the capsule caps and to place the capsule bodies in a row of holes in the capsule body carrier. Means are further provided to place the capsule caps in the aligned row of holes in one of the arcuate plates. When the plates are temporarily misaligned, the row of capsule bodies are filled. The capsules are recapped when the holes in the plates are realigned with the holes in the capsule carrier and then an entire row of capsules are rejected. It will be appreciated that the Smith patent relies quite heavily on reciprocating motion which is, in effect, intermittent whereas in the present invention as will be described more fully hereinafter only a continuous rotary motion is employed.